Haley was born in Houston, Texas, but moved to New Mexico n his youth. He joined the comics industry in 1991 where his first piece of work in the industry was penciling the second TNG annual from DC Comics, "Thin Ice". Soon after, he began working on the Dark Horse title Ghost, and then on Birds of Prey. He eventually began writing and co-creating titles including Gen13: Science Friction and Jack Hunter: GI Spy.

In addition to his comics work, he has done advertising and RPG illustrations for companies including Wizards of the Coast, Adidas, and KenzerCo.